Orthodontic bracket

ABSTRACT

An orthodontic bracket is provided, including a backend surface, a frontend surface, a first side surface, a second side surface, and a passageway. The backend surface is adapted for attachment and is opposite the frontend surface. The first and second side surfaces are connected between the backend surface and the frontend surface. The passageway extends from the first side surface to the second side surface. The cross-section of the passageway includes an access opening, an archwire slot, a path portion, and at least one rotation portion. The access opening is configured to allow the archwire to enter the passageway. The archwire slot is configured to receive the archwire. The path portion connects the access opening and the archwire slot. The rotation portion is provided in the path portion to allow the archwire to change its orientation.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation-In-Part of pending U.S. patentapplication Ser. No. 15/827,184, filed on Nov. 30, 2017 and entitled“ORTHODONTIC BRACKET”, which claims priority of U.S. Provisional PatentApplication No. 62/563,771, filed on Sep. 27, 2017, the entirety ofwhich are incorporated by reference herein.

BACKGROUND OF THE INVENTION Field of the Invention

The present application relates to an orthodontic correction technology;and in particular to an orthodontic bracket designed to receiveorthodontic archwires.

Description of the Related Art

Misaligned teeth can adversely affect a person's dental aesthetics,functions, and health. The goal of orthodontic correction is to bringthe teeth into proper alignment by using appliances which exertmechanical forces to move the teeth to positions or orientations wherethe dental functions and aesthetics are improved.

Conventional braces use archwires and brackets to induce correctiveforce on the teeth. The archwire is pre-shaped and interconnects theteeth through brackets that are fixed to the surfaces of the teeth. Wheninitially installed, the archwire elastically deforms to accommodate themisaligned teeth. The archwire is resilient and exerts forces on theteeth through the brackets to bring the teeth into alignment with thepre-shaped form of the archwire. The archwire exerts continuous forceson the teeth to urge them to their finish positions. Traditional wiresare fixed to the brackets using ligatures and strong forces aretransmitted to the teeth. With self-ligating brackets, archwires canslide more freely in the bracket slot, achieving orthodontic toothmovement with less pressure and discomfort to the patient.

Prior art discloses self-ligating brackets consisting of a main bracketbody attached to a base. An archwire slot extends mesial-distally acrossthe main bracket body and between the gingival and occlusal tie wings.The archwire slot opens edgewise in the opposite direction to the baseto receive an archwire. The bracket further consists of a locking clipwhich allows placement and removal of an archwire in the open positionand slides to lock in place to maintain the archwire in the archwireslot in the closed position. Prior art discloses various locking clipsor closures designed to achieve the same purpose.

Installation of the archwire with the self-ligating brackets requiresspecialized tools designed to manipulate the opening and closing of thelocking clips or closures. Usually, the placement and removal of anarchwire is performed by a person (e.g. dentist) other than the patientwho is not able to perform the task alone. Such manipulations can bedifficult, especially in the case of lingual brackets. The locking clipsor closures add to the complication and cost in the manufacture of theself-ligating brackets. The structure of the locking clips or closuresalso add edges and protrusions to the bracket body which causes morediscomfort to the patient.

It is desirable to make the task of archwire installation easier with animproved bracket design without a locking clip or closure mechanism. Thepresent invention improves upon the deficiencies in prior art devices bysimplifying the design and construction of the bracket while retainingthe archwire retention characteristics of self-ligating brackets.

BRIEF SUMMARY OF THE INVENTION

In some embodiments of the invention, an orthodontic bracket for use incombination with an archwire to apply corrective force to a tooth isprovided. The orthodontic bracket includes a backend surface, a frontendsurface, a first side surface, a second side surface, and a passageway.The backend surface is adapted for attachment. The frontend surface isopposite the backend surface. The first side surface is connectedbetween the backend surface and the frontend surface. The second sidesurface is connected between the backend surface and the frontendsurface and opposite the first side surface. The passageway extends fromthe first side surface to the second side surface. The cross-section ofthe passageway includes an access opening, an archwire slot, a pathportion, and at least one rotation portion. The access opening isconfigured to allow the archwire to enter the passageway. The archwireslot is formed at the end of the passageway to receive the archwire. Thepath portion connects the access opening and the archwire slot. Therotation portion is provided in the path portion to allow the archwireto change its orientation.

In some embodiments of the invention, an orthodontic bracket for use incombination with an archwire to apply corrective force to a tooth isprovided. The orthodontic bracket includes a backend surface, a frontendsurface, a first side surface, a second side surface, and a passageway.The backend surface is adapted for attachment. The frontend surface isopposite the backend surface. The first side surface is connectedbetween the backend surface and the frontend surface. The second sidesurface is connected between the backend surface and the frontendsurface and opposite the first side surface. The passageway extends fromthe first side surface to the second side surface. The cross-section ofthe passageway includes an access opening, an archwire slot, and a pathportion. The access opening is configured to allow the archwire to enterthe passageway. The archwire slot is formed at the end of the passagewayto receive the archwire. The path portion connects the access openingand the archwire slot and has a curved form.

In some embodiments of the invention, an orthodontic bracket for use incombination with an archwire to apply corrective force to a tooth isprovided. The orthodontic bracket includes a backend surface, a frontendsurface, a first side surface, a second side surface, and a passageway.The backend surface is adapted for attachment. The frontend surface isopposite the backend surface. The first side surface is connectedbetween the backend surface and the frontend surface. The second sidesurface is connected between the backend surface and the frontendsurface and opposite the first side surface. The passageway extends fromthe first side surface to the second side surface. The cross-section ofthe passageway includes an access opening, an archwire slot, a pathportion, and at least one notch. The access opening is configured toallow the archwire to enter the passageway. The archwire slot is formedat the end of the passageway to receive the archwire. The path portionconnects the access opening and the archwire slot. The at least onenotch is formed on the first side surface and/or the second side surfacefor retaining an O-ring elastic.

In some embodiments of the invention, an orthodontic bracket for use incombination with an archwire to apply corrective force to a tooth isprovided. The orthodontic bracket includes a backend surface, a frontendsurface, a first side surface, a second side surface, and a passageway.The backend surface is adapted for attachment. The frontend surface isopposite the backend surface. The first side surface is connectedbetween the backend surface and the frontend surface. The second sidesurface is connected between the backend surface and the frontendsurface and opposite the first side surface. The passageway extends fromthe first side surface to the second side surface in an extendingdirection. The cross-section of the passageway including an accessopening, an archwire slot, and a curving path portion. The accessopening is configured to allow the archwire to enter the passageway. Thearchwire slot is formed at the end of the passageway to receive thearchwire. The path portion connects the access opening and the archwireslot. The path portion further includes at least one twisting portiondefined by gradually bending and twisting surfaces, wherein the archwiremust swing away from the extending direction of the passageway to passthrough the bending and twisting surfaces of the twisting portion.

In some embodiments of the invention, an orthodontic bracket for use incombination with an archwire to apply corrective force to a tooth isprovided. The orthodontic bracket includes a backend surface, a frontendsurface, a first side surface, a second side surface, and a passageway.The backend surface is adapted for attachment. The frontend surface isopposite the backend surface. The first side surface is connectedbetween the backend surface and the frontend surface. The second sidesurface is connected between the backend surface and the frontendsurface and opposite the first side surface. The passageway extends fromthe first side surface to the second side surface in an extendingdirection. The cross-section of the passageway including an accessopening, an archwire slot, and a curving path portion. The accessopening is configured to allow the archwire to enter the passageway. Thearchwire slot is formed at the end of the passageway to receive thearchwire. The path portion connects the access opening and the archwireslot. The path portion further includes a protrusion formed in the pathportion, wherein the archwire must be bent around the protrusion to passthrough.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be more fully understood by reading the subsequentdetailed description and examples with references made to theaccompanying drawings, wherein:

FIG. 1A is a perspective view illustrating a pair of counteractingbrackets according to some embodiments of the present invention;

FIG. 1B is a perspective view illustrating a pair of counteractingbrackets with rounded edges on their outer surfaces according to someembodiments of the present invention; and

FIG. 2A is a cross-sectional view illustrating the structural featuresof the pair of counteracting brackets of FIG. 1A;

FIG. 2B is a cross-sectional view illustrating an effective archwireslot area based on the counteracting exit passageway directions of thepair of counteracting brackets of FIG. 2A in direct alignment;

FIG. 3A is a perspective view illustrating an archwire in the archwireslots of the pair of counteracting brackets of FIG. 1A in directalignment;

FIG. 3B is a perspective view illustrating an archwire in the archwireslots of the pair of counteracting brackets of FIG. 3A in directalignment with the archwire in a position of being blocked by thecounteracting passageways;

FIG. 4A is a cross-sectional view illustrating the structural featuresof a counteracting bracket according to some embodiments of the presentinvention;

FIG. 4B is a cross-sectional view illustrating the structural featuresof a counteracting bracket according to some embodiments of the presentinvention;

FIG. 5A is a cross-sectional view illustrating the structural featuresof a pair of counteracting brackets according to some embodiments of thepresent invention;

FIG. 5B is a cross-sectional view illustrating an effective archwireslot area based on the counteracting exit passageway directions of thepair of counteracting brackets of FIG. 5A in direct alignment;

FIG. 6 is a side view illustrating the structural features of a pair ofcounteracting brackets according to some embodiments of the presentinvention;

FIG. 6A schematically shows a twisting portion formed on the pathportion surfaces of a counteracting bracket according to someembodiments of the present invention;

FIG. 6B schematically shows two cross-sections taken at differentelevations L1 and L2 of the bracket in FIG. 6A.

FIG. 7 is a perspective view illustrating a counteracting bracket withO-ring notches according to some embodiments of the present invention;

FIG. 8 is a perspective view illustrating a counteracting bracket withan auxiliary archwire slot, grooves on four sides, and an auxiliarydevice slot according to some embodiments of the present invention;

FIG. 9 schematically shows that a power chain is installed on thecounteracting bracket shown in FIG. 8;

FIG. 10 schematically shows that an uprighting spring is attached to acounteracting bracket for uprighting a tipped tooth; and

FIG. 11 is a perspective view illustrating an application ofcounteracting brackets to a patient removable appliance consisting oftooth cap segments, according to some embodiments of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

In order to illustrate the purposes, features, and advantages of theinvention, the preferred embodiments and drawings of the invention areshown in detail as follows.

In the following detailed description, the orientations of “on”,“above”, “under”, “below”, “left”, and “right” are used for representingthe relationship between the relative positions of each element asillustrated in the drawings, and are not meant to limit the invention.

Moreover, although the terms first, second, third, fourth etc. may beused in the following detailed description to describe various elements,regions or sections, these elements, regions or sections should not belimited by these terms. These terms are only used to distinguish oneelement, region or section from another element, region or section.Thus, a first element, region or section discussed below could be termeda second element, region or section without departing from the teachingsof the present invention.

In addition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed. Variousfeatures may be arbitrarily drawn in different scales for the sake ofsimplicity and clarity.

Embodiments of the present invention disclose an orthodontic bracketdesign with a locking system that does not use a locking clip or closurefor entrapping an archwire in the archwire slot. The locking systemrequires the deployment of at least two counteracting (orthodontic)brackets. FIG. 1A is a perspective view illustrating a pair ofcounteracting brackets according to some embodiments of the presentinvention. The top of the figure points to the occlusal direction, andthe bottom of the figure points to the gingival direction. The pair ofcounteracting brackets includes a gingival access bracket 100 and anocclusal access bracket 200.

The gingival access bracket 100 includes a main body 101 connected to abase 102. The base 102 has a backend surface S1 (cannot be seen in FIG.1A due to limited viewing angle) adapted for attachment to a surface,e.g., the labial surface or lingual surface, of a tooth (not shown). Thebackend surface S1 can be bonded to a surface of a tooth by adhesive(e.g., light-cure adhesive), for example. Alternatively, the backendsurface S1 can be bonded to a mounting base adapted to fit a tooth in acustomized setup. The main body 101 has a frontend portion 101A oppositethe base 102. The frontend portion 101A has a smooth curved frontendsurface S2 opposite the backend surface S1. In some embodiments, whenviewed from the frontend surface S2, the gingival access bracket 100 isshaped in rectangular, square, circular, oval, rhombus, parallelogram,or shield shape.

In addition, the main body 101 and the base 102 of the gingival accessbracket 100 collectively have two opposite side surfaces S3, S4 (onlyone side surface S3 can be seen in FIG. 1A due to limited viewing angle)connected between the backend surface S1 and frontend surface S2. Insome embodiments, as shown in FIG. 1B, some of the outer surfaces (e.g.,the backend surface S1, the frontend surface S2, and/or the sidesurfaces S3, S4) of the gingival access bracket 100 are designed withrounded edges to minimize discomfort to the patient.

The main body 101 further has a passageway 103 formed therein andextending from the side surface S3 to the side surface S4 for receivingan archwire 30 (see FIGS. 3A and 3B). The passageway 103 forms an accessopening 103A on an end of the main body 101 facing toward the gingivaldirection, for allowing the archwire 30 to enter the passageway 103.

In some embodiments, the main body 101 and the base 102 may comprise thesame material, such as metal, metal alloys, ceramics, resins, plastics,or other materials suitable for use in oral applications. In addition,the main body 101 and the base 102 may be integrally formed inone-piece. For example, the main body 101 and the base 102 may be madeof a metal material and may be formed in one piece by metal injectionmolding (MMA). Alternatively, the main body 101 and the base 102 may beindividually produced parts with the same or different materials asdescribed above and may be assembled together via adhesive, welding, orother boding methods. In some alternative embodiments, the main body 101may also comprise multiple parts and/or multiple materials. Brackets ofthe present invention may be manufactured in multiple parts, but isassembled to provide the inherent functionality.

Similarly, the occlusal access bracket 200 includes a main body 201connected to a base 202. The base 202 has a backend surface S1 (cannotbe seen in FIG. 1A due to limited viewing angle) adapted for attachmentto a surface, e.g., the labial surface or lingual surface, of a tooth(not shown). The backend surface S1 can be bonded to a surface of atooth by adhesive (e.g., light-cure adhesive), for example.Alternatively, the backend surface S1 can be bonded to a mounting baseadapted to fit a tooth in a customized setup. The main body 201 has afrontend portion 201A opposite the base 202. The frontend portion 201Ahas a smooth curved frontend surface S2 opposite the backend surface S1.In some embodiments, when viewed from the frontend surface S2, theocclusal access bracket 200 is shaped in rectangular, square, circular,oval, rhombus, parallelogram, or shield shape.

In addition, the main body 201 and the base 202 of the occlusal accessbracket 200 collectively have two side surfaces S3, S4 (only one sidesurface S3 can be seen in FIG. 1A due to limited viewing angle)connected between the backend surface S1 and frontend surface S2. Insome embodiments, as shown in FIG. 1B, some of the outer surfaces (e.g.,the backend surface S1, the frontend surface S2, and/or the sidesurfaces S3, S4) of the occlusal access bracket 200 are designed withrounded edges to minimize discomfort to the patient.

The main body 201 further has a passageway 203 formed therein andextending from the side surface S3 to the side surface S4 for receivingan archwire 30 (see FIGS. 3A and 3B). The passageway 203 forms an accessopening 203A on an end of the main body 201 facing toward the occlusaldirection, for allowing the archwire 30 to enter the passageway 203.

The material and manufacturing method of the main body 201 and the base202 of the occlusal access bracket 200 are similar to the main body 101and the base 102 of the gingival access bracket 100 and are thus notrepeated here.

The gingival access bracket 100 and the occlusal access bracket 200 forma counteracting set. Without specifying the (archwire) access direction,either the gingival access bracket 100 or the occlusal access bracket200 can be called a counteracting bracket. The counteracting bracketsmay be used as labial brackets as well as lingual brackets in someembodiments. To achieve the counteracting effect of archwire entrapment,which will be further explained in the following paragraphs, any twoadjacent counteracting brackets can be deployed in counteracting pairswhere a gingival access bracket is paired with an occlusal accessbracket. However, individual bracket can also achieve archwire retentionvia some features such as a curved passageway (see FIG. 2A) or at leastone turn provided in the passageway (see FIG. 4B), without usingadditional locking clips or closures, in some alternative embodiments.

FIG. 2A is a cross-sectional view illustrating the structural featuresof the pair of counteracting brackets of FIG. 1A. As shown, thecross-section of the passageway 103 of the gingival access bracket 100is designed to include an access opening 103A, an archwire slot 103B,and a curved path portion 103C. The access opening 103A is configured toallow an archwire 30 (FIGS. 3A and 3B) to enter the passageway 103 (asdepicted by an arrow in the figure). The archwire slot 103B is formed atthe end of the passageway 103. The curve path portion 103C connects thearchwire slot 103B and the access opening 103A. In some embodiments, thecurved path portion 103C extends from the archwire slot 103B firsttoward the frontend portion 101A and then curves back toward the base102 before bending toward the gingival direction at the access opening103A. As shown in FIG. 2A, the curved path portion 103C has a width W toallow an archwire 30 to traverse the length of the path portion 103C tobe placed or received in the archwire slot 103B. In some embodiments,the width W of the entire path portion 103C is consistent or varied. Insome embodiments, an archwire 30 can enter the access opening 103A andfollow the curved path portion 103C in a generally clockwise orcounterclockwise direction to enter the archwire slot 103B of thegingival access bracket 100.

On the other hand, the cross-section of the passageway 203 of theocclusal access bracket 200 is designed to include an access opening203A, an archwire slot 203B, and a curved path portion 203C. Theconfiguration, structure, and function of the access opening 203A,archwire slot 203B and path portion 203C are similar to those of theaccess opening 103A, archwire slot 103B and path portion 103C of thegingival access bracket 100 and are thus not repeated here. In someembodiments, an archwire 30 can enter the access opening 203A and followthe curved path portion 203C in a generally counterclockwise orclockwise direction to enter the archwire slot 203B of the occlusalaccess bracket 200.

The maximum archwire size allowed is determined by the size of thearchwire slots 103B and 203B. In some embodiments, as shown in FIG. 2A,both the archwire slots 103B and 203B have a rectangular cross-section(as depicted by dotted rectangles in the figure) which corresponds tothe cross-sectional shape of the received archwire (not shown). However,the archwire slots 103B and 203B can accommodate an archwire withdifferent cross-sectional shapes. For example, an archwire of circularor square cross-sectional shape may also be received in the archwireslots 103B and 203B with rectangular cross-section.

In some embodiments, the width W of the narrowest part of the pathportion 103C, 203C is greater than the short side but less than the longside of the rectangular cross-section of an archwire. Accordingly, thearchwire is allowed to pass through the path portion 103C and the pathportion 203C in a substantially fixed orientation (i.e., withoutrotation). Moreover, excessive twisting of the archwire during traversalalong the path portions 103C and 203C can be avoided.

FIG. 2B shows an overlap of the cross-sections of the pair ofcounteracting brackets of FIG. 2A in direct alignment. In particular,the archwire slot 103B of the gingival access bracket 100 is inalignment with the archwire slot 203B of the occlusal access bracket200. For an archwire (not shown) to exit the archwire slot 103B, itneeds to follow the path portion 103C of the gingival access bracket 100in the exit direction indicated by a solid arrow in FIG. 2B. However,the archwire is prevented from exiting by the passageway wall 203E ofthe occlusal access bracket 200. On the other hand, for the archwire toexit the archwire slot 203B, it needs to follow the path portion 203C ofthe occlusal access bracket 200 in the exit direction indicated by adashed arrow in FIG. 2B. Again, the archwire is prevented from exitingby the passageway wall 103E of the gingival access bracket 100. As aresult, the overlap of the passageway walls 103E and 203E forms aneffective archwire slot area when the cross-sections of thecounteracting brackets 100 and 200 are in direct alignment. The combinedeffect of two adjacent brackets in a basic counteracting pair maintainsthe archwire in the archwire slots without a clip or closure mechanism.

FIG. 3A is a perspective view illustrating an archwire in the archwireslots of the pair of counteracting brackets of FIG. 1A in directalignment. As shown, after installation, an archwire 30 is placed in thearchwire slot 103B of the gingival access bracket 100 and in thearchwire slot 203B of the occlusal access bracket 200, wherein the twobrackets are in direct alignment. In some embodiments, the archwire 30is a thermal Nickel-Titanium (Ni—Ti) wire, which is flexible at roomtemperature and can be easily installed by the doctor or patient. Inactual deployment to a dental arch, some adjacent brackets are lined upalong a curve while others are in irregular positions. Furthermore, thebackend surface S1 of the bracket 100, 200 can be designed withdifferent tilt angles and/or shapes to fit different shapes of teeth, orthe backend surface S1 of the bracket 100, 200 can be attached to acustomized mounting base adapted to fit a tooth's surface, so that thosebrackets are in alignment.

FIG. 3B shows the situation where the archwire 30 shifts toward thefrontend portions 101A and 201A of the brackets 100 and 200. Arrowsdepicted in the figure indicate that the archwire 30 comes into contactwith the passageway walls 103E and 203E. As a result, the archwire 30 isprevented from exiting the passageways 103 and 203, thereby achievingthe counteracting effect of archwire entrapment without using a clip orclosure mechanism.

It should be appreciated that many variations and modifications can bemade to the embodiments of the present disclosure. For example, FIGS. 4Aand 4B are cross-sectional views illustrating various structuralfeatures of a counteracting bracket (a gingival access bracket 100 isused as an example for illustrate) according to some alternativeembodiments. As shown in FIG. 4A, the path portion 103C of thepassageway 103 is designed to be straight in cross-section, and an angleα such as about 90 degrees is formed between the path portion 103C andthe archwire slot 103B (i.e. the straight path portion 103C is designedto be substantially perpendicular to the archwire slot 103B). However,the angle α may also have another available degrees (e.g., more thanabout 30 degrees). As shown in FIG. 4B, the path portion 103C of thepassageway 103 is designed to include at least one turn or bendingdesign in cross-section. The turn or turns provided in the path portion103C prevent a received archwire from escaping easily from thepassageway 103 spontaneously.

FIG. 5A is a cross-sectional view illustrating the structural featuresof a pair of counteracting brackets according to some alternativeembodiments. As shown, compared with the embodiment shown in FIG. 2A,the cross-section of the passageway 103 of the gingival access bracket100 further includes a rotation portion 103D provided in the curved pathportion 103C, and the cross-section of the passageway 203 of theocclusal access bracket 200 further includes a rotation portion 203Dprovided in the curved path portion 203C. In some embodiments, therotation portion 103D, 203D may be circular in cross-section as shown inFIG. 5A, but the invention is not limited thereto.

The rotation portions 103D and 203D are configured to allow an archwire30 to rotate to change its orientation (the dotted circles in thepassageways 103 and 203 depicted in the figure represents that thearchwire 30 may rotate in the rotation portions 103D and 203D) beforeentering the archwire slots 103B and 203B. In some embodiments, thewidth W′ of the rotation portion 103D (e.g. the diameter of the circularrotation portion 103D) is greater than the (maximum) width W of the pathportion 103C, and the width W′ of the rotation portion 203D (e.g. thediameter of the circular rotation portion 203D) is greater than the(maximum) width W of the path portion 203C, so as to allow the archwire30 to change its orientation. In addition, the rotation portion 103D maybe positioned near the archwire slot 103B or at any position of the pathportion 103C, and the rotation portion 203D may be positioned near thearchwire slot 203B or at any position of the path portion 203C.

In some alternative embodiments, as shown in FIG. 6, the cross-sectionof the passageway 103 of the gingival access bracket 100 may furtherinclude a plurality of (e.g., two or more than two) rotation portions103D separately formed in the path portion 103C, and the cross-sectionof the passageway 203 of the occlusal access bracket 200 may furtherinclude a plurality of (e.g., two or more than two) rotation portions203D separately formed in the path portion 203C, to allow an archwire 30to rotate to change its orientation.

Accordingly, the doctor or patient can manually turn segments of thearchwire 30 to their original orientations at the rotation portions 103Dand 203D, so that the stress loading on the archwire 30 due to twistingis released before the archwire 30 enters the archwire slots 103B and203B.

It should be appreciated that the above design of the rotation portions103D and 203D may also be integrated with the embodiments as describedabove. On the other hand, in the cases of no rotation portion providedin the path portion 103C, 203C of the bracket 100, 200 (e.g., theembodiments shown in FIGS. 2A to 4B), the path portion 103C, 203C mayalso be designed to have a sufficient width to allow an archwire 30 tochange its orientation freely during traversal from the access opening103A, 203A to the archwire slot 103B, 203B along the path portion 103C,203C (that is to say, the path portion 103C, 203C with a sufficientwidth can also achieve the function of the rotation portion).

In addition, as shown in FIG. 6, the passageway wall 103E of thepassageway 103 and the passageway wall 203E of the passageway 203 mayrespectively have at least one portion that is tilted with respect tothe extension direction of the passageway 103 and the passageway 203(i.e. the direction into the paper as shown in the figure) to form anuneven surface 103F, 203F. The uneven surface 103F, 203F requires anarchwire 30 to be manipulated to twist, thereby increasing thedifficulty for the archwire 30 to pass through this section of thepassageway 103, 203 to prevent the archwire 30 from escaping easily fromthe passageway 103, 203 spontaneously.

In some embodiments of the present invention as shown in FIGS. 6A and6B, the curving path portion 203C further includes a twisting portiondefined by gradually bending and twisting surfaces 203T which areadjacent to path portion surfaces that are substantially parallel to theextending direction E of the passageway 203, the passageway 203extending from the first side surface to the second side surface of theorthodontic bracket. Referring to FIGS. 6A and 6B, when a round archwire30A enters passageway 203, it is parallel to the extending direction E.As the archwire 30A enters the twisting portion defined by the graduallybending and twisting surfaces 203T, the archwire 30A starts to swingtoward one direction as indicated by the shown solid arrow. FIG. 6Bshows two cross-sections taken at different elevations L1 and L2 in FIG.6A. When the archwire 30A reaches the end of the twisting portion, thearchwire 30A can swing back to be parallel to the extending direction Eand enter the archwire slot. Note that the archwire 30A is preventedfrom exiting the archwire slot and the passageway when the archwire 30Ais parallel to the extending direction E. The archwire 30A must swingtoward one direction indicated by the solid arrow to exit.

In some embodiments of the present invention (see FIG. 5A), at least oneprotrusion P is formed on a side of the path portion 103C, 203C of thebracket 100, 200, and at least one depression R is formed on the otherside of path portion 103C, 203C to correspond to the protrusion P.During the installation of an archwire 30, the doctor or patient canmanipulate the archwire 30 to go around the protrusion P of the bracket100, 200 to enter the archwire slot 103B, 203B. The protrusion P isconfigured to prevent an archwire 30 received in the archwire slot 103B,203B from escaping easily from the passageway 103, 203 spontaneously. Insome embodiments, the protrusion P may be a bump or island structurepositioned near the side surface S3, S4, or between the side surfaces S3and S4 (FIG. 1A) of the bracket 100, 200. In some alternativeembodiments, the path portion 103C and/or 203C may have multipleprotrusions P.

FIG. 5B shows an overlap of the cross-sections of the pair ofcounteracting brackets of FIG. 5A in direct alignment, wherein anotherprotrusion P1 is also provided in the path portions 103C and 203C andpositioned between the archwire slot 103B, 203B and the rotation portion103D, 203D to lead to a reduction of the size of the effective archwireslot area that is formed by the passageway walls 103E and 203E, so thatan archwire 30 can be well confined in the effective archwire slot areawithout using additional locking clips or closures. It should beappreciated that the above designs of the protrusion P and/or theprotrusion P1 may also be integrated with other embodiments of thepresent invention as described above.

FIG. 7 is a perspective view illustrating a counteracting bracket (anocclusal access bracket 200 is used as an example for illustration) withO-ring notch features according to some alternative embodiments. Asshown, a pair of O-ring notches 222 is formed on the side surfaces S3and S4 of the frontend portion 201A near the frontend surface S2.Alternatively or additionally, another pair of O-ring notches 222 (notshown) may be formed on the side surfaces S3 and S4 of the frontendportion 201A near the passageway wall 203E. An O-ring elastic O, such asa rubber O-ring, can be easily retained by the O-ring notches 222.

In some embodiments, the O-ring notches 222 are positioned near thearchwire slot 203B, as shown in FIG. 7. By installing an O-ring elasticO at this position, an additional barrier is created in the passageway203 to keep an archwire (not shown) in the archwire slot 203B. Thisfeature allows a counteracting bracket to be used in single bracketapplications. Also, deployment of counteracting brackets to a dentalarch may encounter a situation of severe positional (or level)discrepancies between adjacent brackets that requires an O-ring elasticO to ensure entrapment of the archwire in the archwire slot 203B. Itshould also be appreciated that the O-ring notches 222 may also allowthe deployment of counteracting brackets in other configurations withmultiple brackets, as long as the O-ring elastic O can be retained bythe O-ring notches 222 to prevent an archwire from escaping the archwireslot 203B.

FIG. 8 is a perspective view illustrating a counteracting bracket (anocclusal access bracket 200 is used as an example for illustration) withadditional features, including an auxiliary archwire slot, grooves onfour sides, and an auxiliary device slot, according to some alternativeembodiments. As shown, an occlusal access bracket 200 includes anauxiliary archwire slot 226 (as depicted by a dotted rectangle in thefigure) in addition to the archwire slot 203B. The auxiliary archwireslot 226 is formed in the path portion 203C of the passageway 203,parallel to the archwire slot 203B, for accommodating an auxiliaryarchwire (not shown in the figure for the purpose of simplicity andclarity). In some embodiments, the auxiliary archwire slot 226 hassimilar structure and size with the archwire slot 203B, and/or theauxiliary archwire has similar structure and size with the archwire 30(FIGS. 3A-3B). The auxiliary archwire slot 226 allows an auxiliaryarchwire to be installed in the case of lingual brackets to compensatefor the positional (or level) offset between canines and firstpremolars, for example. Alternatively, an auxiliary archwire slot 226may be formed in the body of the bracket, in a position away from thepassageway 203 and the archwire slot 203B.

To keep an auxiliary archwire in the auxiliary archwire slot 226, twoO-ring elastics O (not shown in the figure for the purpose of simplicityand clarity) can be installed in the O-ring notches 222 near theauxiliary archwire slot 226 (for example, a pair of O-ring notches 222above and another pair of O-ring notches 222 below the auxiliaryarchwire slot 226). However, it should be appreciated that manyvariations and modifications can be made to the embodiments of thedisclosure.

Still referring to FIG. 8, the occlusal access bracket 200 furtherincludes two power chain grooves 224 formed on opposing ends (facingtoward the occlusal and gingival directions) of the occlusal accessbracket 200, parallel to the archwire slot 203B, and positioned betweenthe archwire slot 203B and the backend surface S1, for receiving orretaining a power chain elastic PC (see FIG. 9) that is commonly usedfor orthodontic treatment. Alternatively or additionally, the occlusalaccess bracket 200 may include two power chain grooves 225 formed on theside surfaces S3, S4 (only one power chain groove 225 formed on the sidesurface S3 can be seen in FIG. 8 due to limited viewing angle) andpositioned between the archwire slot 203B and the backend surface S1 forreceiving or retaining a power chain elastic PC. In some embodiments,the power chain grooves 224 and 225 may also be used to accommodateanother type of orthodontic elastic. Note that the power chain grooves224 and/or 225 are positioned a certain distance from the archwire slot203B near the backend surface S1, which prevents an installed powerchain from contacting an archwire in the archwire slot 203B.

As shown in FIG. 8, the occlusal access bracket 200 further includes anauxiliary device slot 228 formed therein. In some embodiments, theauxiliary device slot 228 is extended from an end of the occlusal accessbracket 200 (e.g. an end of the occlusal access bracket 200 near theaccess opening 203A) to its interior or further to extend to theopposite end of the occlusal access bracket 200. Moreover, the auxiliarydevice slot 228 may be positioned a certain distance behind or in frontof the archwire slot 203B, and it provides a means to attach anauxiliary device to the orthodontic bracket. One application is toattach an uprighting spring TS to the auxiliary device slot 228 (seeFIG. 10), so as to apply a force by the uprighting spring TS to thearchwire 30 and the connected brackets (not shown), thereby uprightingtipped tooth or teeth. An uprighting spring TS is commonly used inorthodontics and is thus not illustrated further. It should be notedthat the uprighting spring TS received in the auxiliary device slot 228does not contact or affect an archwire in the archwire slot 203B. Insome embodiments, an extended base portion is formed below the powerchain grooves 224 with a thickness sufficient to allow an auxiliarydevice slot 228 to pass through it, wherein the auxiliary device slot228 passes below the power chain grooves 224.

In addition to fixed braces applications, the counteracting bracketsdescribed above can also be used in patient removable appliances. FIG.11 is a perspective view illustrating an application of counteractingbrackets to a patient removable appliance consisting of tooth capsegments, according to some embodiments of the present invention. Asshown, the appliance includes three tooth cap segments, including afirst anchorage segment 41, a second anchorage segment 42, and anuprighting tooth cap 40. The uprighting tooth cap 40 is installed on atooth U which requires uprighting correction. The first anchoragesegment 41 and the second anchorage segment 42 respectively have severalcounteracting brackets 100 and 200 fixed to the tooth cap segmentsurface. The uprighting tooth cap 40 has a counteracting bracket 100 or200 fixed to the uprighting tooth cap surface. It should be appreciatedthat any pair of adjacent counteracting brackets 100 and 200 havecounteracting exit passageways as described above.

The procedure to install the appliance is as follow. First, theuprighting tooth cap 40, the first and second anchorage segments 41 and42 are installed on the dental arch D without an archwire attached.Next, segments of the archwire 30 are installed on the counteractingbrackets 100 and 200 of the uprighting tooth cap 40, the first andanchorage segment 41 and 42. The archwire installation can be performedby the patient easily due to the counteracting brackets. In someembodiments, the tooth cap segments 40, 41, and 42 may be comprised ofsegments of aligners, retainers or positioners.

As described above, the counteracting bracket of the present disclosureimproves upon the conventional self-ligating bracket in terms ofconstruction, ease of use and patient discomfort. The counteractingbracket has a simplified design without a locking clip or closuremechanism. The dental professional is released from the demanding taskof manipulating tiny locking clips or closure mechanisms. Finally, withthe removal of additional edges and protrusions of a locking clip orclosure mechanism, a simple and easy-to-use bracket is created withsmooth surfaces and rounded edges, which reduces patient discomfort. Inanother aspect, the ease of use also allows the counteracting bracket tobe applied in patient removable appliances.

Although embodiments of the present disclosure and their advantages havebeen described in detail, it should be understood that various changes,substitutions and alterations can be made herein without departing fromthe spirit and scope of the disclosure as defined by the appendedclaims. For example, it will be readily understood by those skilled inthe art that many of the features, functions, processes, and materialsdescribed herein may be varied while remaining within the scope of thepresent disclosure. Moreover, the scope of the present application isnot intended to be limited to the particular embodiments of the process,machine, manufacture, composition of matter, means, methods and stepsdescribed in the specification. As one of ordinary skill in the art willreadily appreciate from the disclosure of the present disclosure,processes, machines, manufacture, compositions of matter, means,methods, or steps, presently existing or later to be developed, thatperform substantially the same function or achieve substantially thesame result as the corresponding embodiments described herein may beutilized according to the present disclosure. Accordingly, the appendedclaims are intended to include within their scope such processes,machines, manufacture, compositions of matter, means, methods, or steps.In addition, each claim constitutes a separate embodiment, and thecombination of various claims and embodiments are within the scope ofthe disclosure.

What is claimed is:
 1. An orthodontic bracket for use in combinationwith an archwire to apply corrective force to a tooth, the orthodonticbracket comprising: a backend surface adapted for attachment; a frontendsurface opposite the backend surface; a first side surface connectedbetween the backend surface and the frontend surface; a second sidesurface connected between the backend surface and the frontend surface,opposite the first side surface; and a passageway extending from thefirst side surface to the second side surface, the cross-section of thepassageway including an access opening, an archwire slot, a pathportion, and at least one rotation portion, wherein the access openingis configured to allow the archwire to enter the passageway, thearchwire slot is formed at the end of the passageway to receive thearchwire, the path portion connects the access opening and the archwireslot, and the rotation portion is provided in the path portion to allowthe archwire to change its orientation.
 2. The orthodontic bracket asclaimed in claim 1, wherein the frontend surface is a smooth curvedsurface.
 3. The orthodontic bracket as claimed in claim 1, wherein thebackend surface, the frontend surface, the first side surface, and/orthe second side surface are designed with rounded edges.
 4. Theorthodontic bracket as claimed in claim 1, wherein the width of therotation portion is greater than the width of the path portion.
 5. Theorthodontic bracket as claimed in claim 1, wherein the path portion iscurved.
 6. The orthodontic bracket as claimed in claim 1, wherein thepath portion is straight.
 7. The orthodontic bracket as claimed in claim1, wherein the path portion includes at least one turn.
 8. Theorthodontic bracket as claimed in claim 1, wherein the passagewayfurther includes a plurality of rotation portions separately provided inthe path portion.
 9. The orthodontic bracket as claimed in claim 1,wherein the archwire slot has a rectangular cross-section.
 10. Theorthodontic bracket as claimed in claim 1, further comprising at leastone notch formed on the first side surface and/or the second sidesurface, for retaining an O-ring elastic.
 11. The orthodontic bracket asclaimed in claim 1, wherein the passageway further includes at least oneauxiliary archwire slot provided in the path portion, parallel to thearchwire slot, for accommodating at least one auxiliary archwire. 12.The orthodontic bracket as claimed in claim 1, further comprising atleast two grooves formed on opposing ends of the orthodontic bracket andpositioned between the archwire slot and the backend surface, forreceiving a power chain elastic.
 13. The orthodontic bracket as claimedin claim 1, further comprising at least one auxiliary device slotextending from an end of the orthodontic bracket to its interior, forreceiving an uprighting spring.
 14. An orthodontic bracket for use incombination with an archwire to apply corrective force to a tooth, theorthodontic bracket comprising: a backend surface adapted forattachment; a frontend surface opposite the backend surface; a firstside surface connected between the backend surface and the frontendsurface; a second side surface connected between the backend surface andthe frontend surface, opposite the first side surface; and a passagewayextending from the first side surface to the second side surface in anextending direction, the cross-section of the passageway including anaccess opening, an archwire slot, and a curving path portion, whereinthe access opening is configured to allow the archwire to enter thepassageway, the archwire slot is formed at the end of the passageway toreceive the archwire, and the path portion connects the access openingand the archwire slot, wherein the path portion further includes atleast one twisting portion defined by gradually bending and twistingsurfaces, wherein the archwire must swing away from the extendingdirection of the passageway to pass through the bending and twistingsurfaces of the twisting portion.
 15. An orthodontic bracket for use incombination with an archwire to apply corrective force to a tooth, theorthodontic bracket comprising: a backend surface adapted forattachment; a frontend surface opposite the backend surface; a firstside surface connected between the backend surface and the frontendsurface; a second side surface connected between the backend surface andthe frontend surface, opposite the first side surface; and a passagewayextending from the first side surface to the second side surface in anextending direction, the cross-section of the passageway including anaccess opening, an archwire slot, and a curving path portion, whereinthe access opening is configured to allow the archwire to enter thepassageway, the archwire slot is formed at the end of the passageway toreceive the archwire, and the path portion connects the access openingand the archwire slot, wherein the path portion further includes aprotrusion formed in the path portion, wherein the archwire must be bentaround the protrusion to pass through.
 16. An orthodontic bracket foruse in combination with an archwire to apply corrective force to atooth, the orthodontic bracket comprising: a backend surface; a frontendsurface opposite the backend surface; a first side surface connectedbetween the backend surface and the frontend surface; a second sidesurface connected between the backend surface and the frontend surface,opposite the first side surface; and a passageway extending from thefirst side surface to the second side surface, the cross-section of thepassageway including an access opening, an archwire slot, and a pathportion, wherein the access opening is configured to allow the archwireto enter the passageway, the archwire slot is formed at the end of thepassageway to receive the archwire, and the path portion connects theaccess opening and the archwire slot and has a curved form.
 17. Anorthodontic bracket for use in combination with an archwire to applycorrective force to a tooth, the orthodontic bracket comprising: abackend surface; a frontend surface opposite the backend surface; afirst side surface connected to and between the backend surface and thefrontend surface; a second side surface connected between the backendsurface and the frontend surface, opposite the first side surface; and apassageway extending from the first side surface to the second sidesurface, the cross-section of the passageway including an accessopening, an archwire slot, a path portion, and at least one notch,wherein the access opening is configured to allow the archwire to enterthe passageway, the archwire slot is formed at the end of the passagewayto receive the archwire, the path portion connects the access openingand the archwire slot, and the at least one notch is formed on the firstside surface and/or the second side surface for retaining an O-ringelastic.
 18. The orthodontic bracket as claimed in claim 17, wherein theat least one notch is positioned near the archwire slot.
 19. Theorthodontic bracket as claimed in claim 17 wherein the passagewayfurther includes at least one auxiliary archwire slot provided in thepath portion, parallel to the archwire slot, for accommodating at leastone auxiliary archwire.
 20. The orthodontic bracket as claimed in claim19 wherein the passageway further includes at least one additional notchformed on the first side surface and/or the second side surface near theauxiliary archwire slot, for retaining at least one additional O-ringelastic.